Key Facts Ordinance Text Full Breakdown Violations FAQ Sources More in Beaverton

Beaverton, OR Accessory Structures: ADU Rules (2026)

Some Restrictions

Compiled from the official code textEditor Martyn O'NeillLast verified August 2026

ADU rules in Beaverton, OR, also called accessory dwelling unit regulations or granny flat ordinances, cover setbacks, owner-occupancy, parking, and permit requirements.

Key Facts

Permit type: Type 1 (Director decision)
Max new floor area: 800 sq ft
Conversion exception: No cap if converting existing floor
Required with: One single-detached dwelling
Detached ADU setback option: 5 ft if ≤15 ft tall

ADU Eligibility Quick-Check

An Accessory Dwelling Unit (ADU) is a smaller, independent living unit on the same lot as a single-family home: converted garages, detached cottages, basement or attic conversions, and attached additions all qualify. Most states have streamlined ADU permitting since 2020, but local rules still control size, height, and setback.

Is your lot zoned single-family or multi-family residential?
Does your lot have at least 1,200 sq ft of buildable space?
Is your existing home owner-occupied (in most states this is not required, but some require it for ADU permits)?
Will the ADU stay under your state's size cap (commonly 850-1,200 sq ft for detached)?
Can you provide one off-street parking space (waived in many states within 0.5 mi of transit)?

If you answered 'yes' to most of these, you likely qualify in Oregon under recent ADU streamlining laws. The Beaverton, OR rules below cover local size, height, and setback requirements.

Summary

Beaverton allows one accessory dwelling unit per single-detached home through a staff-level Type 1 permit, capped at 800 square feet unless it converts existing floor area.

A. An accessory dwelling unit is permitted only in conjunction with a single-detached dwelling. ... C. Size 1. Accessory dwelling units shall not exceed 800 square feet in floor area, except as provided in subsection 2. 2. Accessory dwelling units that result from the conversion of a level or floor of the primary dwelling are not subject to the size limitations in Section 60.50.03.2.C.1 and may occupy the entire level or floor.

View official code

Full Breakdown

Inside Beaverton, Washington County, Oregon, an accessory dwelling unit is permitted only alongside a single-detached dwelling: it can be a converted garage, attic, or basement, added floor area, or a new detached unit. Applicants file a single ADU application, decided by the Director under the Type 1 (staff-level) procedure rather than a public hearing. New ADU floor area is capped at 800 square feet, but a unit created by converting an existing level or floor of the primary house (basement, attic, second story) can occupy the entire level with no 800-square-foot cap, provided no new square footage is added.

Violations & Fines

Building without an approved ADU application, or exceeding the 800-square-foot cap outside the conversion exception, is a Development Code violation; the Director can deny, condition, or revoke the permit.

Frequently Asked Questions

How big can a Beaverton ADU be?

New floor area is capped at 800 square feet, but converting an existing basement, attic, or floor of the house isn't subject to that cap.

Does a Beaverton ADU need a public hearing?

No: it's a Type 1 application decided administratively by the Director, not a hearing-based process.

Sources & Official References

Other rules in Beaverton

Shed & Carport RulesSome Restrictions Landscaping Rules: Water RestrictionsLight Restrictions ADU Owner OccupancyFew Restrictions Tiny HomesSignificant Restrictions Garage ConversionsSome Restrictions Fence Regulations: Fence Permit RequirementsSome Restrictions Animal Ordinances: Wildlife FeedingSome Restrictions Animal Ordinances: Pet Store RulesHeavy Restrictions Public Conduct: JaywalkingSome Restrictions Building Safety: Plumbing PermitsSome Restrictions

All Beaverton rules

How Beaverton compares: Easiest Cities to Build an ADU·Compare Beaverton to another location·View the Oregon accessory structures overview

See something wrong?

Help us keep this page accurate. If you notice an error or outdated information, let us know.

ADU Rules in Nearby Cities

How other cities in Washington County handle adu rules.

Hillsboro, OR